Field of the Invention
The present invention generally relates to the field of warning systems. More particularly, the present invention relates to the field of audible and/or visual warning systems for use in vehicular lifts.
Description of the Prior Art
Specifically, safety is always the most important concern in the use of wheelchair lifts. Many improvements have been accomplished in the past years in designing and manufacturing different types of wheelchair lifts. Related standards for wheelchair lifts are established by, for example, Society of Automotive Engineers (SAE) to provide industrial standards to monitor and test wheelchair lifts. All wheelchair lift manufacturers must enforce and follow related industrial standards to ensure the products delivered are safe and reliable.
In SAE standard No. J2093, there is a threshold warning requirement for wheelchair lifts. Specifically, the standard states that each wheelchair lift shall include a threshold warning system to give an audible and/or visual warning to a wheelchair passenger approaching the lift to a vehicle floor level that the lift platform is more than one (1) inch below the vehicle floor level and the warning system sensor shall cover an access area not less than eighteen (18) inches away from a threshold.
It is desirable to provide a threshold warning system which meets the SAE standard No. J2093 mentioned above.